Numerous stochastic Newton methods using (REF ) or (REF ) with various types of convergence guarantees have been proposed [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}. We review these related references later and point to [13]} for a recent brief survey. However, the existing approaches to stochastic Newton methods share common limitations, which we now discuss.
